Land bridges are the causeways of biodiversity. When they form, organisms are introduced into a new patchwork of species and habitats, forever altering the ecosystems into which they flow; and when land bridges disappear or fracture, organisms are separated into reproductively isolated populations that can evolve independently. More than this, land bridges play a role in determining global climates through changes to moisture and heat transport and are also essential factors in the development of biogeographic patterns across geographically remote regions.

In this book, paleobotanist Alan Graham traces the formation and disruption of key New World land bridges and describes the biotic, climatic, and biogeographic ramifications of these land masses’ changing formations over time. Looking at five land bridges, he explores their present geographic setting and climate, modern vegetation, indigenous peoples (with special attention to their impact on past and present vegetation), and geologic history. From the great Panamanian isthmus to the boreal connections across the North Atlantic and North Pacific Oceans that allowed exchange of organisms between North America, Europe, and Asia, Graham’s sweeping, one-hundred-million-year history offers new insight into the forces that shaped the life and land of the New World.

AUTHOR BIOGRAPHY

Alan Graham is curator of paleobotany and palynology at the Missouri Botanical Garden. He is the author of several books, including Late Cretaceous and Cenozoic History of Latin American Vegetation and Terrestrial Environments and A Natural History of the New World: The Ecology and Evolution of Plants in the Americas, the latter also published by the University of Chicago Press.

REVIEWS

“Graham is among the best paleobotanists in the world. In multiple works, he has synthesized vast amounts of information to produce a paleo perspective on plant diversity through the last hundred million years. Within those works, he has touched on the role of land bridges, but not with the attention shown here. The topic is clear and timely, and this highly original work has great potential to contribute to the biogeographical history of the Americas.”

— Paul Manos, Duke University

“Land Bridges attempts to reconstruct the broad outlines of the geological and paleobotanical history of the last hundred million years. The history of plate tectonics—how it influenced past plant migration, current composition of regional floras, and intercontinental linkages—makes this book a great pleasure to read. While reading, admiration gradually increases for how Graham is able to make a fascinating story out of such a large bulk of evidence. Few scientists have developed such an impressive, integrated picture of earth history. Spectacular.”

— Henry Hooghiemstra, University of Amsterdam

TABLE OF CONTENTS

Abbreviations, Time Scale, and Conversions
Preface

Protocols and Organization
References

Introduction

References

Additional References

Part I: Boreal Land Bridges

Bering Land Bridge

Beringia
Background

References

Additional References

One / West Beringia: Siberia and Kamchatka

Siberia

Geographic Setting and Climate
Geology
Modern Vegetation
Indigenous People

Kamchatka

Geographic Setting and Climate
Modern Vegetation
Indigenous People

References

Additional References

Two / East Beringia: Alaska, Northwestern North America, and the Aleutian Connection

Geographic Setting and Climate
Geology
Modern Vegetation
Indigenous People
Utilization of the Bering Land Bridge
Peopling of America (from the West)
References

Land bridges are the causeways of biodiversity. When they form, organisms are introduced into a new patchwork of species and habitats, forever altering the ecosystems into which they flow; and when land bridges disappear or fracture, organisms are separated into reproductively isolated populations that can evolve independently. More than this, land bridges play a role in determining global climates through changes to moisture and heat transport and are also essential factors in the development of biogeographic patterns across geographically remote regions.

In this book, paleobotanist Alan Graham traces the formation and disruption of key New World land bridges and describes the biotic, climatic, and biogeographic ramifications of these land masses’ changing formations over time. Looking at five land bridges, he explores their present geographic setting and climate, modern vegetation, indigenous peoples (with special attention to their impact on past and present vegetation), and geologic history. From the great Panamanian isthmus to the boreal connections across the North Atlantic and North Pacific Oceans that allowed exchange of organisms between North America, Europe, and Asia, Graham’s sweeping, one-hundred-million-year history offers new insight into the forces that shaped the life and land of the New World.

AUTHOR BIOGRAPHY

Alan Graham is curator of paleobotany and palynology at the Missouri Botanical Garden. He is the author of several books, including Late Cretaceous and Cenozoic History of Latin American Vegetation and Terrestrial Environments and A Natural History of the New World: The Ecology and Evolution of Plants in the Americas, the latter also published by the University of Chicago Press.

REVIEWS

“Graham is among the best paleobotanists in the world. In multiple works, he has synthesized vast amounts of information to produce a paleo perspective on plant diversity through the last hundred million years. Within those works, he has touched on the role of land bridges, but not with the attention shown here. The topic is clear and timely, and this highly original work has great potential to contribute to the biogeographical history of the Americas.”

— Paul Manos, Duke University

“Land Bridges attempts to reconstruct the broad outlines of the geological and paleobotanical history of the last hundred million years. The history of plate tectonics—how it influenced past plant migration, current composition of regional floras, and intercontinental linkages—makes this book a great pleasure to read. While reading, admiration gradually increases for how Graham is able to make a fascinating story out of such a large bulk of evidence. Few scientists have developed such an impressive, integrated picture of earth history. Spectacular.”

— Henry Hooghiemstra, University of Amsterdam

TABLE OF CONTENTS

Abbreviations, Time Scale, and Conversions
Preface

Protocols and Organization
References

Introduction

References

Additional References

Part I: Boreal Land Bridges

Bering Land Bridge

Beringia
Background

References

Additional References

One / West Beringia: Siberia and Kamchatka

Siberia

Geographic Setting and Climate
Geology
Modern Vegetation
Indigenous People

Kamchatka

Geographic Setting and Climate
Modern Vegetation
Indigenous People

References

Additional References

Two / East Beringia: Alaska, Northwestern North America, and the Aleutian Connection

Geographic Setting and Climate
Geology
Modern Vegetation
Indigenous People
Utilization of the Bering Land Bridge
Peopling of America (from the West)
References